The present invention relates to disc brakes, in particular for motor vehicles.
A disc brake, in particular for a motor vehicle, comprises two pads, each intended to cooperate with a lateral face of the disc to be braked under the action of means of control.
These means of control generally comprise a piston mounted so that it is axially mobile, parallel to the disc axis, in a caliper adapted to straddle the disc; the piston is adapted to cooperate with the pad facing it, according to a zone called support zone.
Each pad is constituted by a metal support carrying a friction lining, said metal support being symmetrical with respect to a plane called plane of symmetry, which is perpendicular to it and which is parallel to the disc axis.
It is known that by de-centering the point of application of the braking force due to the piston, i.e. therefore by displacing the piston axis with respect to said plane of symmetry, by arranging it at a transverse distance from the latter, the wear on the friction lining is evened out, parallel to the plane of the metal support, which makes it possible to achieve the maximum benefit from the wear volume of the friction lining.
It is also known that a displacement as above makes it possible to resolve, in certain applications, the problems of noise linked with the rubbing of the friction lining against the facing material, namely the disc to be braked.
Of course these displacements are different; the first being linked with the brake itself, which leads to its being modified by arranging, between the piston and the metal support, an anti-noise shim provided with an opening, said opening, when the pad is mounted in the brake, being found to be arranged at right angles with the piston support zone.
The anti-noise shim being advantageously fixed to the metal support, for example by bonding, it is understood that this requires the arrangement of two different pads for the brakes placed on the left or right with respect to the longitudinal plane of symmetry of the vehicle in question, in particular when the disc brake is of the floating caliper type, the inner pad then being subjected to the action of the piston and the outer pad to the reaction of the caliper integral with the cylinder in which the piston moves; this is also true when the caliper is of the fixed type, each pad being subjected to the action of a piston, the two pistons moving in cylinders arranged in the caliper on either side of the disc.